Field of the Invention
The present invention relates to a display panel and an inspection method thereof.
Discussion of the Related Art
Recently, display devices, such as liquid crystal displays (LCDs), organic light-emitting diode (OLED) display devices, plasma display panels (PDPs), and electrophoretic displays (EPDs), have been fabricated using several types of fabrication processes. After a display panel is completed using such a fabrication process, an auto-probe inspection process of determining whether or not a defect is present in signal lines (e.g., data lines) and subpixels SPs formed on the display panel is performed.
In display devices, display panels have the function of displaying images. The auto-probe inspection process, which is also referred to as a lighting test, is a process of inputting an inspection signal to a display panel to determine whether or not the display panel operates ordinarily in response to the inspection signal. In order to perform such an auto-probe inspection process, an inspection section for supplying inspection signals and an input pad section for receiving signals from an external system are formed in a pad area of the display panel. A plurality of output pads is arranged on an output pad section of the inspection section, and is connected to data lines in an active area. The auto-probe inspection process determines, for example, whether a defect is present in data lines disposed in the active area, whether a defect is present in subpixels, or whether there is a defect in luminance, by supplying an inspection signal to the data lines from the output pad section.
However, a drive integrated circuit (IC) mounted on the pad area depending on the model or resolution of the display device does not use all of the output pads disposed on the output pad section. The non-used output pads are dummy pads present between active output pads that are used. When all of the output pads of the output pad section are not used, the data lines disposed in the active area are disconnected from the non-used output pads, such that resistance differences ΔR are formed by the non-used output pads during the auto-probe inspection process.
Therefore, when a specific gray-scale pattern or a white pattern is displayed on the display panel to determine whether or not a defect is present in the active area using the auto-probe inspection process, a defect in luminance (e.g., a dimmed area) is formed in an area of the non-used pads due to a resistance difference formed by the non-used pads. In other words, although the display panel is fully operational, a defect in luminance in the display panel according to the related art may occur during the auto-probe inspection process, thereby lowering the precision of the inspection process.